FIG. 4 shows an exemplary inspection apparatus having a conventional mounting device. Such an inspection apparatus includes: a mounting device 1, provided in an inspection chamber, for lifting up and down a target object W (e.g., a semiconductor wafer); an XY stage for moving the mounting device 1 in X and Y directions; a probe card 3 disposed above the XY stage 2; and an alignment mechanism 4 for performing alignment between a plurality of probes 3A of the probe card 3 and the semiconductor wafer W on the mounting device 1. The inspection apparatus tests electrical characteristics of the semiconductor wafer W by making electrical contacts between the probes 3A and the semiconductor wafer W which have been aligned. The alignment mechanism 4 further has a lower camera 4A attached to the mounting device 1 and an upper camera 4B capable of moving to a position directly under the probe card 3.
As shown in, e.g., FIGS. 5A and 5B, the mounting device 1 has a mounting table 1A for mounting thereon the semiconductor wafer W, an elevation driving mechanism (not shown) for lifting up and down the mounting table 1A, and a rotational driving mechanism 1B (hereinafter, referred to as “θ direction driving mechanism”) for rotating the mounting table 1A within a predetermined angle in a circumferential direction (hereinafter, referred to as “θ direction”). The elevation driving mechanism vertically moves the mounting table 1A when the semiconductor wafer W needs to be delivered or inspected. The θ direction driving mechanism 1B rotates the mounting table 1A, which can be temporarily raised pneumatically, in the θ direction within a predetermined angle, thus performing the alignment between the semiconductor wafer W and the probes 3A.
The θ direction driving mechanism 1B will be described in more detail with reference to FIGS. 5A and 5B. As can be seen from FIGS. 5A and 5B, the θ direction driving mechanism 1B has a motor 1C provided near the mounting table 1A; a ball screw 1D extending from the motor 1C in a tangential direction of the mounting table 1A; a moving body 1E movably attached to the ball screw 1D; a protrusion 1F horizontally protruded from a circumferential surface of the mounting table 1A; a link 1G for connecting the moving body 1E and the protrusion 1F; and a linear guide mechanism 1H, provided under the moving body 1E, for linearly guiding the moving body 1E. One end portion of the link 1G is axially supported with respect to a shaft of the moving body 1E via, e.g., a bearing, and the other end of the link 1G is axially supported with respect to a shaft of the protrusion 1F via a linear bush. The shaft of the protrusion 1F may be a spline shaft. Moreover, a reference numeral 1I indicates an encoder.
If the θ direction driving mechanism 1B is driven during the alignment between the semiconductor wafer W and the probes 3A, the moving body 1E moves linearly along the ball screw 1D. The linear movement of the moving body 1E is converted to a rotational movement of the mounting table 1A via the link 1G while raising the mounting table 1A via the linear bush. When the alignment between the semiconductor wafer W and the probes 3 is completed by rotating the mounting table 1A in a predetermined angle, the motor 1C stops, and the mounting table 1A is lowered along the linear bush (or the spline shaft) from the position where the mounting table 1A was raised and stops. Techniques for pneumatically raising the mounting table 1A are disclosed in Patent Documents 1 and 2.
Patent Document 1: Japanese Patent Laid-open Application No. H07-307368
Patent Document 2: Japanese Patent Laid-open Application No. H11-288985
However, as shown in FIGS. 5A and 5B, the conventional θ direction driving mechanism 1B is constructed by a link mechanism for converting the linear movement of the moving body 1D to the rotational movement of the mounting table 1A. Thus, the link mechanism needs to be designed precisely, and efforts are required for installation of the link mechanism, thereby increasing costs therefor. Further, a high-priced linear bush (or spline shaft) is used as the elevation mechanism of the mounting table 1A, so that the costs increase further.